Cirsium occidentale

Cirsium occidentale, commonly known as cobwebby thistle or western thistle, is a biennial or short-lived perennial herb in the daisy family (Asteraceae) native to California and adjacent regions of the western United States, especially coastal hills, chaparral, and open slopes. The plant forms a stout, erect stem typically 40 to 200 centimeters tall, conspicuously covered in dense, white, cobwebby tomentum that gives the species its name. The deeply pinnatifid leaves bear spiny lobes and are similarly white-woolly, especially beneath. Large nodding or erect flower heads, 3 to 6 centimeters across, are subtended by spiny, cobwebby phyllaries and display showy disc florets ranging from white and pale pink to deep red or purple depending on variety. The achenes are smooth, oblong, and topped by a feathery, plumose pappus that aids in wind dispersal. Several intergrading varieties occur across the species' range.